I,ve got a 1978 John deere 316, with a Kohler single cyl. engine. I think its a 16 or 17 HP. It has the points and condenser, and the coil like a car has. I made a new battery cable for it , and ended up crossing the cables when reconnecting the battery. Now when I try to start the mower . it will start as long as the key in held in the start position. As soon as the key is released the engine dies. I replaced the key switch and it still does the same thing. Does anyone know what could be causing this problem ?